Implement cross-origin attributes using access check interceptors.

third_party/WebKit/Source/bindings/core/v8/custom/V8WindowCustom.cpp

Index: third_party/WebKit/Source/bindings/core/v8/custom/V8WindowCustom.cpp
diff --git a/third_party/WebKit/Source/bindings/core/v8/custom/V8WindowCustom.cpp b/third_party/WebKit/Source/bindings/core/v8/custom/V8WindowCustom.cpp
index 70f3293c83182cacd79ceca9f8c3eca49c390726..b7b71ff3bda690d3ff8d5ab226ff96ecc20daa0b 100644
--- a/third_party/WebKit/Source/bindings/core/v8/custom/V8WindowCustom.cpp
+++ b/third_party/WebKit/Source/bindings/core/v8/custom/V8WindowCustom.cpp
@@ -142,6 +142,8 @@ void V8Window::openerAttributeSetterCustom(
     const v8::PropertyCallbackInfo<void>& info) {
   v8::Isolate* isolate = info.GetIsolate();
   DOMWindow* impl = V8Window::toImpl(info.Holder());
+  // TODO(dcheng): Investigate removing this, since opener is not really a
+  // cross-origin property (so it shouldn't be accessible to begin with)
   ExceptionState exceptionState(ExceptionState::SetterContext, "opener",
                                 "Window", info.Holder(), isolate);
   if (!BindingSecurity::shouldAllowAccessTo(currentDOMWindow(info.GetIsolate()),
@@ -289,23 +291,20 @@ void V8Window::namedPropertyGetterCustom(
     return;
   }
 
-  // If the frame is remote, the caller will never be able to access further
+  // This is a cross-origin interceptor. Check that the caller has access to the
   // named results.
-  if (!frame->isLocalFrame())
+  if (!BindingSecurity::shouldAllowAccessTo(
+          currentDOMWindow(info.GetIsolate()), window,
+          BindingSecurity::ErrorReportOption::DoNotReport)) {
+    BindingSecurity::failedAccessCheckFor(info.GetIsolate(), frame);
     return;
+  }
 
   // Search named items in the document.
   Document* doc = toLocalFrame(frame)->document();

[haraken, 2016/12/08 08:21:02]

What happens if the frame is a remote frame? Does
BindingSecurity::shouldAllowAccessTo return false for a remote frame?

[dcheng, 2016/12/08 09:04:10]

Yes, BindingSecurity will always return false in that case. I combined the two
cases to avoid having to call failedAccessCheckFor() twice.

   if (!doc || !doc->isHTMLDocument())
     return;
 
-  // This is an AllCanRead interceptor.  Check that the caller has access to the
-  // named results.
-  if (!BindingSecurity::shouldAllowAccessTo(
-          currentDOMWindow(info.GetIsolate()), window,
-          BindingSecurity::ErrorReportOption::DoNotReport))
-    return;
-
   bool hasNamedItem = toHTMLDocument(doc)->hasNamedItem(name);
   bool hasIdItem = doc->hasElementWithId(name);